The current application is the second revision of our application responding to Program Announcement PA-07-114. Our proposed study will examine substance abuse, juvenile/criminal justice system involvement and health disparities in youth, focusing on comparisons between African American and White youth. African Americans comprise about 12% of the US population, but they represented almost half of the prison population in 2004. Increases in arrests for drug offenses have accounted for nearly one third of the growth of the African American inmate population in recent decades. However, findings from national community surveys have shown that rates of substance use and abuse in African Americans are similar to those of Whites. Also, studies have shown that African Americans are less likely to receive adequate treatment for substance use related problems. There is a need to understand racial/ethnic disparities related to juvenile/criminal justice system involvement, substance use and access to treatment for substance use related problems. The proposed project utilizes data from three nationally representative surveys of youth: (1) a large community sample with information on criminal justice system involvement histories, substance use/abuse/dependence, and use of substance treatment services;(2) a longitudinal (7-year) survey of youth covering substance use, delinquent behaviors, juvenile/criminal justice system involvement and risk factors at the individual, family and community levels;and (3) a large, nationally representative sample of youth in placement in Juvenile Justice facilities. Study aims: (1) To examine rates of Juvenile/Criminal Justice System involvement among youth, especially among those with substance use or abuse/dependence, comparing African American and White youth, and identifying factors which may partially explain the differences between the two groups;(2) Using longitudinal data, to examine racial/ethnic differences in the relationship between substance use and juvenile/criminal justice involvement, including the role of substance use in pathways to criminal justice involvement from adolescence to young adulthood, as well as the impact of criminal/juvenile justice system involvement on subsequent changes in patterns of substance use;and (3) To examine differences in the types of treatment received for substance use related problems by African-American and White youth with juvenile/criminal justice system involvement, and identify barriers to use of treatment services faced by African-American youth with juvenile justice system involvement. Public Health Relevance: Given that African American youth are disproportionately represented among juvenile and adult arrestees and prisoners/detainees, especially for drug offenses, and that treatment services for substance use related problems for people involved in the criminal/juvenile justice system tend to be lacking or inadequate, there is a great need to understand the racial/ethnic disparities related to juvenile/criminal justice system involvement, substance use and access to treatment for substance use related problems. The proposed study will examine these racial/ethnic disparities in terms of the dynamic longitudinal relationship between substance use and juvenile/criminal justice system involvement, and in terms of access to treatment services for substance use related problems, from a public health perspective.